Fix authorized_key FQCN and add ansible.posix to CI collections

ansible.posix.authorized_key replaces the bare module name removed
in ansible-core 2.x.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitea/workflows/lint.yml

@@ -25,7 +25,7 @@ jobs:
       - name: Install ansible-lint and collections
         run: |
           python3 -m pip install ansible-lint --break-system-packages --quiet
-          ~/.local/bin/ansible-galaxy collection install community.general community.postgresql
+          ~/.local/bin/ansible-galaxy collection install community.general community.postgresql ansible.posix
 
       - name: Run ansible-lint
         working-directory: ansible

ansible/roles/common/tasks/main.yml

@@ -11,7 +11,7 @@
     validate: visudo -cf %s
 
 - name: Ensure admin SSH key is authorized
-  authorized_key:
+  ansible.posix.authorized_key:
     user: "{{ admin_user }}"
     key: "{{ admin_ssh_key }}"
     state: present